2 Unix SMB/CIFS implementation.
4 trivial database library
6 Copyright (C) Andrew Tridgell 1999-2005
7 Copyright (C) Paul `Rusty' Russell 2000
8 Copyright (C) Jeremy Allison 2000-2003
10 ** NOTE! The following LGPL license applies to the tdb
11 ** library. This does NOT imply that all of Samba is released
14 This library is free software; you can redistribute it and/or
15 modify it under the terms of the GNU Lesser General Public
16 License as published by the Free Software Foundation; either
17 version 3 of the License, or (at your option) any later version.
19 This library is distributed in the hope that it will be useful,
20 but WITHOUT ANY WARRANTY; without even the implied warranty of
21 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
22 Lesser General Public License for more details.
24 You should have received a copy of the GNU Lesser General Public
25 License along with this library; if not, see <http://www.gnu.org/licenses/>.
28 #include "tdb1_private.h"
30 /* all contexts, to ensure no double-opens (fcntl locks don't nest!) */
31 static struct tdb1_context *tdb1s = NULL;
33 /* We use two hashes to double-check they're using the right hash function. */
34 void tdb1_header_hash(struct tdb1_context *tdb,
35 uint32_t *magic1_hash, uint32_t *magic2_hash)
38 uint32_t tdb1_magic = TDB1_MAGIC;
40 hash_key.dptr = (unsigned char *)TDB_MAGIC_FOOD;
41 hash_key.dsize = sizeof(TDB_MAGIC_FOOD);
42 *magic1_hash = tdb->hash_fn(&hash_key);
44 hash_key.dptr = (unsigned char *)TDB1_CONV(tdb1_magic);
45 hash_key.dsize = sizeof(tdb1_magic);
46 *magic2_hash = tdb->hash_fn(&hash_key);
48 /* Make sure at least one hash is non-zero! */
49 if (*magic1_hash == 0 && *magic2_hash == 0)
53 /* initialise a new database with a specified hash size */
54 static int tdb1_new_database(struct tdb1_context *tdb, int hash_size)
56 struct tdb1_header *newdb;
60 /* We make it up in memory, then write it out if not internal */
61 size = sizeof(struct tdb1_header) + (hash_size+1)*sizeof(tdb1_off_t);
62 if (!(newdb = (struct tdb1_header *)calloc(size, 1))) {
63 tdb->last_error = TDB_ERR_OOM;
67 /* Fill in the header */
68 newdb->version = TDB1_VERSION;
69 newdb->hash_size = hash_size;
71 tdb1_header_hash(tdb, &newdb->magic1_hash, &newdb->magic2_hash);
73 /* Make sure older tdbs (which don't check the magic hash fields)
74 * will refuse to open this TDB. */
75 if (tdb->hash_fn == tdb1_incompatible_hash)
76 newdb->rwlocks = TDB1_HASH_RWLOCK_MAGIC;
78 if (tdb->flags & TDB_INTERNAL) {
80 tdb->map_ptr = (char *)newdb;
81 memcpy(&tdb->header, newdb, sizeof(tdb->header));
82 /* Convert the `ondisk' version if asked. */
86 if (lseek(tdb->fd, 0, SEEK_SET) == -1)
89 if (ftruncate(tdb->fd, 0) == -1)
92 /* This creates an endian-converted header, as if read from disk */
94 memcpy(&tdb->header, newdb, sizeof(tdb->header));
95 /* Don't endian-convert the magic food! */
96 memcpy(newdb->magic_food, TDB_MAGIC_FOOD, strlen(TDB_MAGIC_FOOD)+1);
97 /* we still have "ret == -1" here */
98 if (tdb1_write_all(tdb->fd, newdb, size))
108 static int tdb1_already_open(dev_t device,
111 struct tdb1_context *i;
113 for (i = tdb1s; i; i = i->next) {
114 if (i->device == device && i->inode == ino) {
122 /* open the database, creating it if necessary
124 The open_flags and mode are passed straight to the open call on the
125 database file. A flags value of O_WRONLY is invalid. The hash size
126 is advisory, use zero for a default value.
128 Return is NULL on error, in which case errno is also set. Don't
129 try to call tdb1_error or tdb1_errname, just do strerror(errno).
131 @param name may be NULL for internal databases. */
132 struct tdb1_context *tdb1_open(const char *name, int hash_size, int tdb1_flags,
133 int open_flags, mode_t mode)
135 return tdb1_open_ex(name, hash_size, tdb1_flags, open_flags, mode, NULL, NULL);
138 static bool hash_correct(struct tdb1_context *tdb,
139 uint32_t *m1, uint32_t *m2)
141 tdb1_header_hash(tdb, m1, m2);
142 return (tdb->header.magic1_hash == *m1 &&
143 tdb->header.magic2_hash == *m2);
146 static bool check_header_hash(struct tdb1_context *tdb,
147 uint32_t *m1, uint32_t *m2)
149 if (hash_correct(tdb, m1, m2))
152 /* If they use one inbuilt, try the other inbuilt hash. */
153 if (tdb->hash_fn == tdb1_old_hash)
154 tdb->hash_fn = tdb1_incompatible_hash;
155 else if (tdb->hash_fn == tdb1_incompatible_hash)
156 tdb->hash_fn = tdb1_old_hash;
159 return hash_correct(tdb, m1, m2);
162 struct tdb1_context *tdb1_open_ex(const char *name, int hash_size, int tdb1_flags,
163 int open_flags, mode_t mode,
164 const struct tdb1_logging_context *log_ctx,
165 tdb1_hash_func hash_fn)
167 struct tdb1_context *tdb;
171 const char *hash_alg;
172 uint32_t magic1, magic2;
174 if (!(tdb = (struct tdb1_context *)calloc(1, sizeof *tdb))) {
183 tdb->flags = tdb1_flags;
184 tdb->open_flags = open_flags;
186 tdb->log_fn = log_ctx->log_fn;
187 tdb->log_data = log_ctx->log_private;
191 if (name == NULL && (tdb1_flags & TDB_INTERNAL)) {
192 name = "__TDB1_INTERNAL__";
196 tdb->name = (char *)"__NULL__";
197 tdb_logerr(tdb, TDB_ERR_EINVAL, TDB_LOG_USE_ERROR,
198 "tdb1_open_ex: called with name == NULL");
204 /* now make a copy of the name, as the caller memory might went away */
205 if (!(tdb->name = (char *)strdup(name))) {
207 * set the name as the given string, so that tdb1_name() will
208 * work in case of an error.
210 tdb->name = (char *)name;
211 tdb_logerr(tdb, TDB_ERR_OOM, TDB_LOG_ERROR,
212 "tdb1_open_ex: can't strdup(%s)", name);
219 tdb->hash_fn = hash_fn;
220 if (hash_fn == tdb1_incompatible_hash)
221 hash_alg = "tdb1_incompatible_hash";
223 hash_alg = "the user defined";
225 tdb->hash_fn = tdb1_old_hash;
226 hash_alg = "default";
229 /* cache the page size */
230 tdb->page_size = getpagesize();
231 if (tdb->page_size <= 0) {
232 tdb->page_size = 0x2000;
235 /* FIXME: Used to be 5 for TDB_VOLATILE. */
236 tdb->max_dead_records = 0;
238 if ((open_flags & O_ACCMODE) == O_WRONLY) {
239 tdb_logerr(tdb, TDB_ERR_EINVAL, TDB_LOG_USE_ERROR,
240 "tdb1_open_ex: can't open tdb %s write-only",
247 hash_size = TDB1_DEFAULT_HASH_SIZE;
248 if ((open_flags & O_ACCMODE) == O_RDONLY) {
250 /* read only databases don't do locking */
251 tdb->flags |= TDB_NOLOCK;
254 /* internal databases don't mmap or lock, and start off cleared */
255 if (tdb->flags & TDB_INTERNAL) {
256 tdb->flags |= (TDB_NOLOCK | TDB_NOMMAP);
257 if (tdb1_new_database(tdb, hash_size) != 0) {
258 tdb_logerr(tdb, tdb->last_error, TDB_LOG_ERROR,
259 "tdb1_open_ex: tdb1_new_database failed!");
265 if ((tdb->fd = open(name, open_flags, mode)) == -1) {
266 tdb_logerr(tdb, TDB_ERR_IO, TDB_LOG_ERROR,
267 "tdb1_open_ex: could not open file %s: %s",
268 name, strerror(errno));
269 goto fail; /* errno set by open(2) */
272 /* on exec, don't inherit the fd */
273 v = fcntl(tdb->fd, F_GETFD, 0);
274 fcntl(tdb->fd, F_SETFD, v | FD_CLOEXEC);
276 /* ensure there is only one process initialising at once */
277 if (tdb1_nest_lock(tdb, TDB1_OPEN_LOCK, F_WRLCK, TDB_LOCK_WAIT) == -1) {
278 tdb_logerr(tdb, tdb->last_error, TDB_LOG_ERROR,
279 "tdb1_open_ex: failed to get open lock on %s: %s",
280 name, strerror(errno));
281 goto fail; /* errno set by tdb1_brlock */
285 if (read(tdb->fd, &tdb->header, sizeof(tdb->header)) != sizeof(tdb->header)
286 || strcmp(tdb->header.magic_food, TDB_MAGIC_FOOD) != 0) {
287 if (!(open_flags & O_CREAT) || tdb1_new_database(tdb, hash_size) == -1) {
289 errno = EIO; /* ie bad format or something */
293 rev = (tdb->flags & TDB_CONVERT);
294 } else if (tdb->header.version != TDB1_VERSION
295 && !(rev = (tdb->header.version==TDB1_BYTEREV(TDB1_VERSION)))) {
301 tdb->flags &= ~TDB_CONVERT;
303 tdb->flags |= TDB_CONVERT;
304 tdb1_convert(&tdb->header, sizeof(tdb->header));
306 if (fstat(tdb->fd, &st) == -1)
309 if (tdb->header.rwlocks != 0 &&
310 tdb->header.rwlocks != TDB1_HASH_RWLOCK_MAGIC) {
311 tdb_logerr(tdb, TDB_ERR_CORRUPT, TDB_LOG_ERROR,
312 "tdb1_open_ex: spinlocks no longer supported");
316 if ((tdb->header.magic1_hash == 0) && (tdb->header.magic2_hash == 0)) {
317 /* older TDB without magic hash references */
318 tdb->hash_fn = tdb1_old_hash;
319 } else if (!check_header_hash(tdb, &magic1, &magic2)) {
320 tdb_logerr(tdb, TDB_ERR_CORRUPT, TDB_LOG_USE_ERROR,
322 "%s was not created with %s hash function we are using\n"
323 "magic1_hash[0x%08X %s 0x%08X] "
324 "magic2_hash[0x%08X %s 0x%08X]",
326 tdb->header.magic1_hash,
327 (tdb->header.magic1_hash == magic1) ? "==" : "!=",
329 tdb->header.magic2_hash,
330 (tdb->header.magic2_hash == magic2) ? "==" : "!=",
336 /* Is it already in the open list? If so, fail. */
337 if (tdb1_already_open(st.st_dev, st.st_ino)) {
338 tdb_logerr(tdb, TDB_ERR_IO, TDB_LOG_USE_ERROR,
340 "%s (%d,%d) is already open in this process",
341 name, (int)st.st_dev, (int)st.st_ino);
346 tdb->map_size = st.st_size;
347 tdb->device = st.st_dev;
348 tdb->inode = st.st_ino;
351 /* if needed, run recovery */
352 if (tdb1_transaction_recover(tdb) == -1) {
357 /* Internal (memory-only) databases skip all the code above to
358 * do with disk files, and resume here by releasing their
359 * open lock and hooking into the active list. */
360 if (tdb1_nest_unlock(tdb, TDB1_OPEN_LOCK, F_WRLCK) == -1) {
368 { int save_errno = errno;
374 if (tdb->flags & TDB_INTERNAL)
375 SAFE_FREE(tdb->map_ptr);
380 if (close(tdb->fd) != 0)
381 tdb_logerr(tdb, TDB_ERR_IO, TDB_LOG_ERROR,
382 "tdb1_open_ex: failed to close tdb->fd on error!");
383 SAFE_FREE(tdb->lockrecs);
384 SAFE_FREE(tdb->name);
392 * Set the maximum number of dead records per hash chain
395 void tdb1_set_max_dead(struct tdb1_context *tdb, int max_dead)
397 tdb->max_dead_records = max_dead;
403 * @returns -1 for error; 0 for success.
405 int tdb1_close(struct tdb1_context *tdb)
407 struct tdb1_context **i;
410 if (tdb->transaction) {
411 tdb1_transaction_cancel(tdb);
415 if (tdb->flags & TDB_INTERNAL)
416 SAFE_FREE(tdb->map_ptr);
420 SAFE_FREE(tdb->name);
422 ret = close(tdb->fd);
425 SAFE_FREE(tdb->lockrecs);
427 /* Remove from contexts list */
428 for (i = &tdb1s; *i; i = &(*i)->next) {
435 memset(tdb, 0, sizeof(*tdb));